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Finding the Fourth Proportional to 815.11, 1,222.30 and 259.66

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Solution

The fourth proportional to 815.11, 1,222.30 and 259.66 is: 389.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.11 : 1,222.30 = 259.66 : x
  2. Step 2: Convert to fraction form
    815.11/1,222.30 = 259.66/x
  3. Step 3: Cross multiply
    815.11x = 1,222.30 × 259.66
  4. Step 4: Simplify right side
    815.11x = 317,382.42
  5. Step 5: Solve for x
    x = 317,382.42/815.11
  6. Step 6: Final answer
    x = 389.37

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.